The invention concerns a vent cover for a gas pressure regulator. Some environments that require a gas pressure regulator are extremely dirty. A typical example is in an animal confinement building housing chicken, pig, cow, or other livestock, where, due to the noxious gases and dusty environment, significant ventilation is required to provide adequate breathing air. The ventilation fans cause the lightweight dust from the litter on the floor of the confinement building to become substantially airborne. A typical confinement building for chickens may have more than 4 inches deep of litter on the entire floor of the building where the materials can be very fine particles from wood shavings or rice husks or other absorbent materials. During the period between occupancy in the confinement building it may be necessary to wash down the inside of the building and the equipment in the building to sanitize the environment. Also during the period where the building is not occupied the ventilation fans are not in use and it is common that the atmosphere can become very humid and this leads to condensation on surfaces inside the building. Typical confinement building temperatures when the occupancy period begins have to be maintained such that the animals are in comfortable conditions to promote healthy growth in the case of chickens this temperature is 90 degrees Fahrenheit. Under these harsh conditions it is common that the combination of fine dust, moisture followed by elevated temperatures will form dense concentrations of fine dust. Typically gas pressure regulators are equipped with a very small vent hole which can measure as little as a few thousands of an inch. If the vent hole of the gas pressure regulator becomes clogged with this dense matter it is practically impossible to clean the vent hole and therefore the gas regulator will not operate as intended.
Gas pressure regulators are well known and are particularly useful for controlling the flow of fluids, such as liquid petroleum gas (propane) or natural gas (methane), as they flow into a burner for heating purposes. Gas pressure regulators, such as used to regulate and reduce the gas pressure of natural gas or liquid petroleum gas, received from a relatively high pressure supply must be vented. The venting occurs on the side of the pressure regulating diaphragm not exposed to the gas, and the venting is necessary to allow the diaphragm to move freely without causing a vacuum or pressure condition within the vented cavity as well as allowing an escape for gas that would be released from the relief valve in case an over pressure condition was obtained at the outlet of the regulator. These may be found in gas (methane or propane, for example) or oil furnaces for residential, commercial buildings or process heaters. In the past, such gas pressure regulators were mounted in such a way that accumulation of dust or corrosive substances did not affect the operation of the regulators. Specifically they were positioned in housings, or otherwise mounted in such a way that falling dust would not accumulate on the gas pressure regulator, such as positioning the regulator under a solid surface. Also it is important that periodic wash down not affect the operation of the gas regulator. On the other hand it is important that the regulator be exposed to the variance in air pressure to assure that no matter what the air pressure is, the gas pressure regulator can supply the burner with a constant and steady supply of gas or oil, for example. When a very tight housing surrounds the gas regulator, the regulator cannot be adequately ventilated to the atmosphere and thus will not work satisfactorily. This is not a solution for many very dirty environments.
U.S. Pat. No. 3,985,157 to Ferguson discloses an adjustable regulator vent cover that is exposed to adverse weather conditions such as icing. The vent cover for regulators having an internally threaded vented neck, in combination, a hollow body having inner and outer walls interconnected by a side wall, a first neck-receiving opening defined in said inner wall, a second neck-engaging opening defined in said outer wall coaxial with said first opening of a diameter slightly less than the diameter of the associated regulator neck, a vent opening defined in said side wall, and a cap having a threaded stem receivable within said second opening and a lip concentric to said stem of a diameter greater than the diameter of said second opening adapted to engage said outer wall adjacent said second opening. A gas pervious screen is mounted in the side wall to prevent insects from entering the interior of the gas regulator.